Improvement in mode of attaching erasers to pencils



. away by use.

UNITED STATES PATENT OEEIcE.-

GARDNER L. EoLT, or SPRINGFIELD, MASsAcEUsETTS.

IMPROVEMENT IN MODE OF ATTACHING ERASERS TO PENCILS.

Specification forming` part of Letters Patent No. 86,753, datedFebruary'), 1869.

To all whom it may concern:

Be it known that I, GARDNER L. HOLT, of Springfield, in the county ofHampden and Commonwealth of Massachusetts, have invented a new andImproved Erasing Attachment for Lead-Pencils 5 and I do hereby declarethat the following is a full, clear, and exact description thereof,reference being had to the annexed drawings, making a part of thisspecification, and to the letters of reference marked thereon, in which-Figure l is an elevation of an ordinary leadpencil having my improvedattachment applied thereto. Fig. 2 is an axial sectional view of saidattachment. Fig. 3 is lalso an axial sectional view of the same, therubber being shown as partially crowded out to compensate for wear byturning in the pencil. Fig. 4 shows a modified form of said attachment,the ferrule being divided by a longitudinal cut.

My invention consists of a small cylindrical piece of vulcanizedcaoutchouc, or other similar elastic material, which can be used forerasing the marks made by lead-pencils and cleaning the surface ofpaper, which erasing substance is inserted within a ferrule of thinsheet metal, so that enough of the rubber projects at one end of theferrule to serve as an eraser, while the opposite end of the rubberextends down nearly to the other end of the ferrule. VThe rubber is madeof such a diameter as to lill the ferrule completely and be held withinthe same by its pressure against the sides.

A shallow screw-thread is cut upon the inside of one end of the ferrule,extending a short distance into the ferrule, and, if applied to a woodpencil, the ferrule. can be turned so that the screw-thread will engagewith the wood of the pencil and cut a shallow corresponding malescrew-thread upon the wood, and thus draw the pencil into the ferrule asfar as necessary. By this screw-thread in the ferrule the latter is notonly held firmly upon the pencil, but, by turning the pencil within theferrule, I am also enabled to advance the pencil into the ferrule., andthus push out the rubber as fast as its projecting end is worn Nearlythe whole of the rubber can thus be utilized, while it is kept clean andentire until thrust out at the end of the ferrule.

As the diameters of the wood pencils in market are variable, I constructa modied form of the attachment, in which the ferrule, otherwise formedas before described, is divided by a longitudinal cut on one side, asshown in Fig. 4, so as to clasp tightly the end of the pencil, whetherit is larger or smaller, without trimming the wood so as to enter theferrule.

The construction of my invention, as shown in Fig. l, is as follows: Theferrule A is made of a convenient length-about three-fourths of aninchand of an inside diameter to correspond with the size of pencils towhich it is to be applied, and the interior is smoothly iinished and hasa female screw-thread, c, cut at one end, the thread of which projectsslightly into the ferrule, so as to engage with the wood of the pencil.

In forming the ferrule, the threaded end can be made slightly thickerinside, so as to allow the screw-thread to proj ect beyond the smoothinner face of the ferrule to the depth of the thread, or thereabout.

A small cylindrical piece, B, of erasing material, vulcanizedcaoutchouc, or like erasive substance, is formed, of such a diameter asto press snugly into the ferrule, and long enough at the opposite endfor the pencil to enter the ferrule suiiiciently to attach the lattersecurel y to the former by the screw-thread.

In practice, the erasing-pieces can be readily cut in lengths from acord of vulcanized rub ber of the proper diameter, and thus madeperfectly uniform, while the ferrules can be struck up in the samemanner as cartridgeshells are now made, thus making the whole attachmentvery cheaply and uniformly.

The ferrules may be made of gutta-percha, or hard rubber, or other likematerial.

In operation, it will be seen that as the rubber is worn away at theerasing end the pencil can be screwed further into the ferrule, so as topush the rubber out and maintain the proper projection for erasing, asis shown in Fig. 3, when the pencil has been somewhat advanced. v

In some cases a male screw-thread may be advantageously cut upon thepencil to engage with the femalescrew-thread in the ferrule.

Instead of holding the rubber within the fer rule by its pressureagainst the sides, the rubber may be rigidly cemented to the end of thepencil and then pushed forward, as before described; but I prefer themethod of construction before described as more simple and effectual.

I do not claim, broadly, an erasing-tip so arranged as to slide out of apenei1case, as such a device has been in use; but I believe that anerasing attachment composed of a piece of vulcanized rubber, or likematerial,

` An erasing'attachment for lead-pencils" composed of the ferrule'A,havingthe screwl thread. a formed therein andthe erasing material Bapplied thereto, and the whole con structed and arranged substantiallyas and for the purpose set forth. g

The combination of the ferrule A', divi ded longitudinally, and having afemale screwthread cut therein, and the erasing` material B applied tosuch ferrule, substantially as and for the purpose set forth.

In witness whereof I have hereunto setjmy hand this 22d day of July, A.D. 1868. g

' G. L. HOLT.

Witnesses: J. l). BUCKLAND,

E. F. SOMMER.

